Polylactic acid resins have some features that polylactic acid resins are inexpensive because the polylactic acid resins are produced from L-lactic acid used as a raw material according to a fermentation method from sugars extracted from maize, potato or the like, that the raw materials are derived from plants from which the amount of total carbon dioxide discharged is very small, and that the resins have the properties of being strongly rigid and highly transparent, so that the utilization of the polylactic acid resins is expected at present.
Patent Publication 1 discloses a resin composition containing a polylactic acid resin, and at least two flame retardants selected from bromine-based flame retardants, chlorine-based flame retardants, phosphorus-based flame retardants, nitrogen compound-based flame retardants, silicone-based flame retardants, and other inorganic flame retardants, in order to obtain a resin composition having excellent moldability, mechanical properties, heat resistance, and flame retardant property.
In addition, Patent Publication 2 discloses a polylactic acid resin composition characterized in that a polylactic acid resin is contained as a main component, and the composition is obtained by subjecting a mixture containing a triphenyl phosphate in an amount of from 3 to 30% by mass, a (meth)acrylic ester compound in an amount of from 0.01 to 5% by mass, and a peroxide in an amount of 0.001% by mass or more to melt-kneading, in order to provide a flame retardant, impact-resistant polylactic acid resin composition having excellent heat resistance.
Patent Publication 3 discloses a polylactic acid resin composition containing a polylactic acid resin, a metal hydroxide, a phosphorus-containing compound, and a volatile compound other than the above phosphorus-containing compound, wherein the content of the above phosphorus-containing compound is 10 parts by mass or less, based on 100 parts by mass of a total value of the above polylactic acid resin, in order to provide a polylactic acid resin composition having an excellent balance between flame retardant property and bleeding resistance.